The duration of stage transition during pharyngeal swallowing among young-elderly, and mid-elderly individuals.

[Purpose] Understanding the normal movements of the pharyngeal stage is important in the assessment of dysphagia. This study classified an elderly population into young-elderly and mid-elderly individuals and investigated the difference in stage transition duration between the two groups to provide basic material for assessment of dysphagia in old age. [Subjects and Methods] The subjects of the study were 12 middle-aged individuals (40-49 years), young-elderly individuals (65-74 years), and 9 mid-elderly individuals (75-84 years). Stage transition duration was defined as the time from the moment food boluses passed the ramus of the mandible until the start of upward movement of the hyoid. All image data were measured using a videofluoroscopic study. Difference in measured values for stage transition duration between the groups were confirmed with one-way analysis of variance. [Results] Although analysis of variance was significantly longer in the young-elderly and mid-elderly individuals than in the middle-aged individuals, there was no significant difference in stage transition duration between the young-elderly and mid-elderly individuals. [Conclusion] In this study, there was no significant difference between the young-elderly and mid-elderly individuals in the movement speed of muscles related to pharyngeal swallowing.